Art of casting metals.



A. M. CRAIG.

ART or CASTING hmmm,i

APPLE' GATION FILED DBO.8,1913.

Patented Aug 18, 1914 LVIN M. CRAIG, or NEW HAVEN, CONNECTICUT.

ART oF CASTING METALS.

`iin'mo'os.

Spefciication. of Letters Patent.

Patented Aug. 18, 1914.-

Application tiled December 8, 1913. Serial No. 805,225.

To alw/iorrit17am/concern: n

Be it known that LiALviN M. Curio, a citizen of thc Unitcdl States, residing,r at New Haven, county -New Haven, and State of Connecticut, have invented a new and useful Improvement in the Art of Gasting Metals, of which the following is a full, clear, and exact description.

My invention relates to improvements 1n the art of casting metals, and thek object of my invention is to produce a method or improvement in the art whereby metals can he rapidly east, the metal of the casting compressed during the .operation so that-an cxcecdingly dense casting will he produced, to provide means ofy leaving the surface of the casting smooth, to utilize metal molds for this purpose, to compress the metal so that 'the reaction caused 'by the swell of the ,poured metal and the expansion' of the mold,

can be taken up without injury to either `casting or mold, and use air pressure in such l a way4 that the yexhaust from thejuir pres` sure device can be utilivied to chill the mold and cool the casting. i

Where met-als are cast in n solid mold and then ysubmitted to pressure asin the plunger type of com n'essiou casting: apparatus, there is great lia ility of cracking: .the mold or casting, or of distorting the latter, and this is especially so w'here hydraulic or inelastic Ineens of compression is used, and. where spring sections are used in the molds the pressure is insuiicient, and the heated mold quickly destroys the temper of the springs. In carrying out my invention, however. I use a two-)art mold which is yc vpaiisible both laterally and longitudinally, and which consequently when pressure is appliedy to the mold, permits of compression in all directions. I use an air engine for effecting the compressim sothat the reaction caused by the swelling of the poured metal or mold will act against the air, and I can utilize the engineexhaust for cooling the mold and iletalz""'fThis-`will he best understood by the description which follows.

Reference is t0 be had to the accompanying drawings formingr a part of this specification, in which similar reference characters indicate correspondingr parts in all the views.

Figure l is a broken side elevation oa simpleV form of apparatus capable of carrying my process into operation. Fig. 2 is an enlarged cross section of a closed mold.

Fig. 3 is a perspective view of the two-part mold with the parts slightly separated, and Fig. 4 iS a detail view showing thc pivotal connection between the piston rod and one of the mold sections.

I have shown a very simple incans of carrying the invention into effect, and it will be understood that. very many other forms of apparatus can hc uscd for accomA plishing the saine result. As illustrated the apparatus has a suitable hase frame l0 formed of spaccdapart side rails, and at the -end of the frame are brackets or ahutincnts 11 to one of which is fixed a mold section 12 .comprising half the mold, whilc the op posed section 13 reciprocatcs with relation to the section 12.` Each of these sectionsl is provided with side walls or wings 1l and 15, placed at right angles to cach other, the \edge of the wall 15 abutting with the opthnnold is cli'rscdiis shown in Fig. 2. and the vidrlls 14 arcflpreferably p rovidcd with vraised portions for. shoulders 14 which sct into the mold so as to make a close joint.

At the top thc section 1Q has a cover 1G Closing overthe top of the opposed section 13 when the parts of thc mold are put together, 'and the nnember 125 has a bottom section 17 which closes over thc bottoni of the section l2 so that when the sections are pushed together, the metal can be poured and the mold sections 'are held under prcssure so that ythe metalis greatly condensed, while the .swelling` action ofthe casting,7 or metal, if excessive, will cause the sections of the mold to yield against their elastic backing sufficiently to prcvent breaking oi the mold or casting, or distortion of thc latter.

The mold is provided with a .suitable innate 18 at the top. As a inc-ans of guiding thc rcciprocatilnr mold section 13, it has trucks 19 on thc side running on supporting rails 20. At thc back of the section lf3 it has a loose connection as shown at 21 with a piston rod 22. connecting with the piston of the cylinder 23 which is suitably supported and backed by one of the abutments or brackets 11. The above connection can be made 1by simply passing a pin 2lb through the casing 21a on the back 14 of the mold scctidn and through the piston rod 2Q which enters said casing, although any suitable loose connection between the piston rod and mold can be used. The air is admitted unposed wall 14 of` the other section, when Y duced in ordinary ways.

lthat this arrangement is adapted for rapid der pressure through a three-Way cock 24 having connections at 25 and 26 with the ends of the cylinder 23, and the exhaust also comes back throughA the pige 26 and connects with a pipe 27 leading to the cross-pipe 28, and this has jet openings 29 diseharving upon the sections 12 and i3 when the mold is open. l have not shown the details of the pipe connection with the cylinder 23, or the arrangement of the piston, because this arH rangenient is common to manyv forms of apparatus, and l use any preferred type of air engine and pipe connection.

When the apparatus is. used, the cock 9A. isy turned so as to aetuate the engine, and the piston throws out the rod 22 and slides the section 13 against the section 12 so as to close the mold. The metal is then oured, and air is then admitted tothe cylin er or engine 23 so as to greatly compress and condense the metal in theniold. When the metal is first poured and before it be ins Ito cool, it swells quickly, andthe mol ysections also swell under the heat; but as* the pressure hack of the piston is an elastic onethe mold can react against this pressure, and this yielding of the mold will prevent in'ury' to. either the mold or the casting. Ad itional' pressure can then be admitted to theI eylin der 23 so that the metal While soft can be compressed to any desired extent. The piston in the cylinder 23 isfthen reversed, thus opening the mold,"and the casting can drop` Yfri-ni the mold, being Started manually or otherwise if nccessar 1, As the mold is opened, the exhaust rom the cylinder 23 passes through the pipes 27 and 28, and the expanding air is ,lirectedagainst the mold sections 12- and 13, and the casting in the latter, so that the said parts are quickly chilled. This will he readily understood b`eeauseit is well known that when air is al lowed to expand quickly after being heavily compressed, it absorbs the surroundingr heat to sueh an extent, that the :adjacent parts becomerexceedingly cold.

lt will be seen that by means of this proey l mm get a very dense smooth tine casting, :ind it will he noticed that the air blast will keep the mold cool to a certain extent so that castingr can he carried on continuously and with great rapidity. l ythus get the double advantageof great speed in casting, nud a much better casting than can be pro- It will be seen casting, especially as the mold can be so readily 'pcned and closed` and as provision is made for preventing the mold from being unduly heated. It will also be observed that in my improved process I use a two-part mold which practically forms' a container or bottle in which the liquid is poured, and that I am 'able to apply a' heavy but elastic pressure to the mold in all directions so as to hold the liquid metal against expansion, and thus greatly condense it, and that I use air as the compression means so that in case of extraordinary expansion for any reason, the compression. force is in the nature of a cushion which will permit slight reaction of the mold against the air cushion without danger of breaking the mold. It will also heseen that I can apply the pressure instantly be' cause the mold parts are held firm, and the' liquid met-a1 begins to be condensed as it cools. This is quite different from the process in which plungers are used to squeeze theY into a mold which islaterally'and longitii-l` dinally expansible and applyinv a heavy but elastic nressure tothe moldan timetoset. Y ,MH- 2l Tlieherein descrihedmethod ofrcalstlng `metals, which consists in bringingithe' Inol'd parts together, pouring the 1metal into the. mold, and holding the mold partsftogether' by a heavy but elastic,pressureactingon all.

parte o'f the mold, thereby condensing the molten metal as soon as it is poured,

The herein described method of casting metals, which consists in nouring the melted,

l l metal while Athe metal is still liquid andbefoi'e ithas had metal into aeomprcssible and expansible i mold', forcing the mold sections uponv the metal by an air pressure, and cooling the mold sections when the mold is opened by a blast of compressed air. I

, 4. The herein described method of casting:

metals, which consists i'n' poux-inf.,lr the melted metal in a eompressible and expansible mold,

maintaining the'metal in the mold in conpressed condition by air in an air engine, and directingr the exhaust of theengine upon the mold sections when the mold is opened for the purpose of cooling` said mold seotio'ns.

fitnessesr WVARREN B. HU'rcuINsQN, Aim-mn G. DANNELL.

ALVIN M. CRAIG; l 

